The high-grade phosphate rock from Centrex's Ardmore mine in northwest Queensland was exported by Centrex-subsidiary Agriflex, to a Samsung customer.

That deal follows the binding marketing services agreement Centrex signed with Samsung in February that allocated 20% of Ardmore's production for Samsung to sell into Korea, Japan, Indonesia, India, Mexico and Taiwan.

The shipment to South Korea follows the first two shipments of phosphate rock to New Zealand in the fourth quarter of 2022.

So far Centrex has shipped a total of 59,290t of phosphate rock to customers.

Centrex managing director Robert Mencel said the shipment to Asia was remarkable under the circumstances.

"China is the world's largest producer of phosphate, however, phosphate rock supplies up to the quality of Centrex's phosphate rock product are not yet widely available on the Asian continent," he said.

"We have the utmost confidence that this shipment will open doors for us in the Asian market on account of the quality of our product."

Mencel said the high-grade phosphate rock was also very low in cadmium, a toxic chemical that could be concentrated in crops and cause health problems.